Elastic fluid turbine



March 6,

0. JUNGGREN ELASTIC FLUID TURBINE Filed Sept. 50, 1933 \I 7% %\\l wvllllllllllllll xvi/ll!!! Ill/r I Inventor; Oscar Junflggren,

His Attorney.

Patented Mar. 6, 1934 UNITED STATES PATENT OFFECE ELASTIC FLUID TURBINE New York Application September 30, 1933, Serial No. 691,648

2 Claims.

The present invention relates to elastic fluid turbines, more particularly to the kind of turbines in which the first and second stages include a double-row bucket wheel such as is the case with reversing turbines used for ship propulsion in which the reversing or astern part usually comprises a single, double-row bucket wheel.

In modern turbines, in which elastic fluid at temperatures of 1000 F. and more is used as a drive medium, diificulties occur due to the excessive heating of the first bucket wheels. This is particularly the case in reversing turbines for ship propulsion in which the reversing wheel or wheels normally revolve in the comparatively cool exhaust steam forlong periods of time, and during reversing are suddenly put into action by a blast of very hot, high pressure steam or like elastic fluid. In the case of a double-row wheel having a comparatively massive structure, relative expansion takes place between the wheel and adjacent elements because said wheel is more exposed to the heat of the high temperature elastic fluid.

The object of the present invention is to provide an improved turbine construction to permit relative expansion between the first double-row wheel element and the adjacent elements without thereby setting up undue stresses between said elements.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing which forms a part of my specification.

In Fig. l of the drawing I have shown, by way of example, a sectional view, partly broken away, of a reversing turbine which may be used in ship propulsion, embodying my invention, and in Fig.

2 a cross-sectional View along line 2-2 of Fig. 1.

The turbine comprises a welded outer casing 10, an ahead part having a hollow shaft or drum 11 which in the present instance is integrally formed with disks 12 for carrying buckets 13. Arranged between adjacent bucket disks or wheels are diaphragrns 14, supported by the casing and packed against the drum, for properly directing elastic fluid passing from a higher stage into the succeeding lower stage.

The astern part comprises a stub or shaft 15 having a portion projecting into and engaging an end portion 16 of the drum or shaft 11 of the ahead part. A collar 17 is integrally formed with the stub and is rabbeted at 18 to the end face of the shaft. The rabbet maintains concentric relation between the shaft and the stub. The collar in addition is fastened to the shaft by means of axial bolts 19.

In accordance with my invention I provide a double-row bucket wheel 20 which has a bore 21 co in concentric relation with the circumference of the collar, and defining an annular space therewith. The double-row bucket wheel is fastened to the collar and concentric relation is maintained therebetween by the provision of a plurality of dowel pins 22 projecting through radial holes in the wheel and the collar. At least three radial pins provided at 120 angular degrees are necessary for maintaining concentric relation, but more may be provided in accordance with the dimensions of the wheel. In the drawing I have shown three pins 22 slidably projecting through radial holes in the stub and the wheel. The holes are provided intermediate the two rows of buckets 23 and 24 respectively. A plug 25 screwed into the outer portion of each hole in the bucket wheel prevents the pins 22 from moving radially outward. A diaphragm 26 is interposed in known manner between the two rows of buckets for directing the flow of elastic fluid discharged from the first row 23 in proper direction into the second row 24. The elastic fluid is supplied through a conduit 27 fastened to the casing. During operation a part of the supplied elastic fluid leaks past a space defined between the entrance side of the bucket wheel and the easing into a chamber 28 from which chamber the leakage elastic fluid passes through the space defined between the bucket wheel and the collar of the shaft into the exhaust chamber of the turbine. The high temperature of the elastic fluid causes the bucket wheel to expand relatively more than the stub.

No stresses are thereby set up because with my structure the bucket wheel may expand relatively to the stub or shaft in any direction without causing undesirable stresses.

What I claim as new and desire to secure by Letters Patent of the United States, is,--

1. In an elastic fluid turbine, a shaft, a doublerow bucket wheel for receiving high temperature elastic fluid, the wheel having a bore defining an annular space with the shaft, at least three circumferentially spaced pins slidably projecting through radial holes in the wheel and the shaft intermediate the two rows of buckets, the holes extending completely through the wheel and the pins being inserted between the two rows of buckets in radially inward direction, and means for retaining the pins in the holes.

2. In a reversing turbine, an ahead part havat least three circumferentially spaced pins pr'0- ing a hollow shaft, an astern part having a stub jecting slidably through radial holes in the collar with a portion projecting into and engaging the and the wheel intermediate the buckets, and plugs hollow shaft and a collar rabbeted and bolted screwed into the holes intermediate the buckets 5 to the end face of the shaft, a double-row bucket for retaining the pins in the holes. 80

wheel in concentric, spaced relation to the collar, I OSCAR J UN GGREN. 

